In the course of the game's events, Reptor conspires with Duke Langobalt of Dozel in obtain more power in the continent of Jugdral. He escalated the intensity of the war between Grannvale and Isaach by killing King Mananan of Isaach, who was heading to the Grannvale front to explain Isaach's stand in the war to Prince Kurth of Grannvale.

In Chapter 3, Reptor is seen entering the domains of northern Agustria to arrest Sigurd's army for allegedly plotting to overthrow the Kingdom of Grannvale and aiding in killing Prince Kurth. Sigurd's army manages to flee to the confines of Silesse, where it stays for a considerable amount of time. Reptor later appears once again in Chapter 5, guarding Velthomer Castle with Arvis's Roten Ritter. However, just as Sigurd's army draws up to the Velthomer region, Alvis's forces turn against him, taking him completely by surprise. Alongside getting pounded by the merciless Meteor spells, Sigurd's army manages to override Reptor's forces. Reptor will end up perishing in the process, betrayed and full of shame.

Reptor, with the almighty Mjölnir, is a serious threat to Sigurd's forces, and should not be attacked unless they either have massive attack power or the ability to survive 60 magical damage. Such characters who are capable of doing so include Lewyn with the Forseti tome, Briggid with the Yewfelle bow, Sigurd with the Tyrfing sword, Holyn with the Moonlight Sword skill, Ayra with the Shooting Star skill and a Brave Sword, and Tailto with the Wrath skill and Thoron tome. Reptor's Great Shield skill will also activate rather frequently, and as such, attacks inflicted against him should be carefully planned. However, his low Resistance can be his greatest weakness and make it an easy target to the Silence Staff which make it very easy to eliminate.

Reptor's magic stat is almost literally a game-breaker at 30, which is well above the Baron cap of 22.

Reptor: Sigurd!? ...you traitor! Invading our holy land!!Sigurd: You're the traitor, Lord Reptor! Entrapping my father and Prince Kurth... You know what actually happened!Reptor: Hmph, you idiot! Politics is all about power! Your father had no power, which is why he died. You're a knight, that much should be obvious to you.Sigurd: Knights respect honour and justice, and what you've done isn't just. I've returned to restore Grannvale's reputation!Reptor: You've gone to a lot of trouble, but this is as far as you'll get. You'll die a traitor, just like Vylon. Your strength is nothing compared to my Mjölnir. Soon you'll see how powerless you really are... Mwahaha...

Reptor: Ta, Tailto... It's you. I knew that you were with the rebel army, but I never expected to face you like this...Tailto: Father... I'm so sorry...Reptor: Grr... Claud!! You deceived my daughter... In any case... House Freege's reputation must be defended. Tailto, you have to die.Tailto: ! ...father...